Core drill construction



July 12, 1938." 'AV Q CATLAND ET AL u 25,123,453

` CORE DRILL CONSTRUCTION Filed Aug. l1, 1957 lll Patented July 12, 1938 CORE DRILL oous'rnuo'rloriI Alfred C. Catland, Alhambra, and Philip C. Efromson, Whittier, Calif., assignors to Globe Oil Tools Company, Los Nietos, Calif., a corporation of California Application Agust 11, 1937, serial No.`15s,514

15 claims. (ci. 25a-72) This invention relates to well tools and relates more particularly to a core drill for use in the rotary method of well drilling. A general object of this invention is to provide 'a simplified, de-

pendable and improved bit head construction for a core drill of the character mentioned.

. Another object of this invention is to provide a practical, effective, anti-friction bearing 'means for mounting the roller cutters of a well core drill. Another object of this invention is to provide a well core drill construction of the character mentioned in which the roller cutters are supported entirely by balls to rotate with a minimum of friction. l i Another object of this invention is to provide a core drill construction of the character mentioned in which the several parts of the cutter mountings are securely and dependably fixed to the head or body of the bit.

Anotherobject of this invention is to provide a core drill construction vof the character mentioned in which the assembly of a cutter, its supporting pin and its several bearing elements are held against separation prior to being assembled 25 on the bit head whereby the cutter assembly may be shipped, stored, handled and installed as a unit.

Another object of this invention is to provide a core drill construction of the character men- 30 tioned embodying novel means for securing the ends of the cutter bearing assemblies to the bitv spaced rows of balls, both of which assume the end thrusts in both directions Y radial thrusts.

` The various objects and features. of our inven- 4as well as -the 40 tion will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawing, in which:

Fig. 1 isa central longitudinal detailed sectional view` of the lower portion ofl a core drill embodying the present invention. Fig. 2 is a bottom view of the drill showing the cutters in broken lines. Fig. 3 is an enlarged fragmentary vertical 50 detailed sectional view illustrating one of the outer cutters and its mounting. Fig. 4 is aview similar to Fig. 3 showing one of the inner cutters and its mounting. Fig. 5v is a reduced side l elevation of the C-washer of the bearing means the core.

side elevation of the sectional bushing of theA 4bearing means for one of the inner cutters, and

21, 1937. It is to be understood that the invention is not to be construed as limited or restricted to the speciilc'form or application about to be described.

The core drill illustrated in the drawing includes an outer barrel I0 to le connected with the lower end of a rotary well drilling string. A bit head I I is threaded on the lower end of the barrel IIJ. The bit head II is tubular having a central longitudinal opening I2 and the lower portion of the head II embodies certain features of the invention, as will be hereinafter described. Spaced upwardly facing annular shoulders I3 and lli are provided in the head opening I2. The drill further includes an inner barrel I5 extending longitudinally through the outer barrel I0 and adapted to receive the core. A collar I6 is xed on the lower end of the inner barrel I5 and is received between the shoulder I4 and a downwardly-facing shoulder I1 on the interior of the outer 'barrel I0- to rotatably support lthe inner barrel I5' in the outer barrel. The inner barrel I5 is spaced from the interior of the outerbarrel I0 to leave an annular uid passage I8 for conducting the circulationfluid downwardly. Ports I9.are provided in the collar I6 to conduct the circulation uid from the passage I8 to ports 20 in the head II. The ports 20 discharge the cir-- culation uld to the cutters of the drill, aswill be subsequently described. A core catcher 2l is arranged in the' head II to trap `and retain The core catcher 2I is an annular member or assembly and includes a plurality of circumferentially spaced spring urged dogs 22 projecting inwardly to bite into the core.4 The core catcher 2l is arranged between the shoulder I3 and a downwardly facing shoulder 23 in the collar I6.

In accordance with the invention the lower portion of the head II is formed to receive the cutters and their mounting means. Spaced recesses 24 and 25 extend upwardly in the Wall of upwardly from the bottom of the head I I in said the tubular head II from its lower end. The inner and outer sides of the recesses 24 slope downwardly and inwardly with respect to the central longitudinal axis of the drill.l A tapered boss 26 is provided on the inner wall of each recess 24 to increase the thickness of the inner wall portion of the head `Il adjacent the recesses. Notches 21 extend upwardly from the lower end of the head Il in the inner wall portion of the head to connector join the recesses 24 with the head opening I2. The notches 21 have at substantially vertical side walls. Similar flat walled notches 28 are provided in the outer wall portions of the head Il and join or communicate with the recesses 24. The upper walls of the notches 21 and 28 are inclined downwardly and outwardly with respect to the central vertical axis of the drill and the notches 21 and 28 are radially aligned with respect `to said axis. The recesses 25 are spaced between the spaced recesses 24 and their inner and outer walls are flat and inclined downwardly and outwardly relative to the vertical axis of the drill. A tapered boss 29 is provided on the outer wall of each recess 25 to increase the outer' wall portion of the head II at the recesses. Notches 38 extend outer wall portions of the head and join the recesses 25. The side walls of the notches 3D are flat and substantially vertical. Notches 3I are provided in the inner wall portions of the head II and connect the recesses 25 with the head opening I2. The notches 3l have flat substantially vertical walls and the notches 30 and 3l are substantially\radially aligned. The upper walls of the notches 30 and 3| are inclined down- .wardly and inwardly with respect to the central vertical axis of the drill.

The improved core drill construction of the present invention includes, generally, inner roller cutters A, bearing means for rotatably mounting the cutters A in the recesses 24, outer roller cutters B and bearing means for rotatably mounting the cutters B in the recesses 25. We will first proceed with a detailed description of one of the cutters A and its bearing means.

The cutters -A are provided to assist in making an annular cut in the earth formation at the bottomof the well boreand serve to trim the core for reception in the head opening I2. The several cutters A may be identical and the following description is equally applicable to all of the cutters A. The cutter A has a central longitudinal opening 32 and the ends of the cutter A are preferably fiat. Thecutter A is cylindrical and is provided with suitable peripheral cutting parts or teeth 33. A central tapered socket 34 is provided in the inner end of the cutter A. In accordance with the invention axially spaced ball races are provided in the wall of the cutter opening 32. In the preferred construction illustrated there are two spaced ball races 35 in the wall of the cutter opening 32. The races 35 are partially` circular in cross section and are of substantial depth. v

.The bearing means for.`rotatablysupporting the inner cutters A each includes, generally, a pin 36, a sectional bushing 31 on the pin 36 and series of balls 38 cooperating with the races 35 and the bushing 31 to rotatably support the cutter A.

The bearing pin 36 may be a lsimple cylindrical member, as illustrated. The pin 36 is preferably uniform in diameter throughout its length. The

inner end of the pin 36 relative to the central vertical axis of the drill is flat and pitched with respect to the axis of the pin. The pin 36 passes through the opening 32 of the cutter A and is considerably longer than the cutter.

The bushing 31 is assembled on the pin 36 and extends through the cutter opening 32 'to project `xieyond the opposite ends of the cutter. In accordance with the invention the bushing 31 is sectionaland comprises an inner section 40, a central section 4I and an outer section 42. The bushing sections 40, 4I and 42 are tubular and surround the pin 36. -The bushing sections 40, 4I and 42 are generally cylindrical and may be of the same diameter. The several sections of the bushing 31 are arranged in end to end relation and the bushing is of the same length as the pin 36. The end of the section 40 at the inner end of the pin 36 is fiat and has the same inclination as the end of the pin. The bushing section 42 has its outer end in the same plane as the outer end of the pin 36. The inner bushing section 40 has two flat parallel side faces 43 extending inwardly from its inclined end. The outer bushing section 42 has two similar at side faces 44 extending inwardly from its fiat outer end. The sections 40, 4| and 42 of the bushing 31 are arranged in abutting relation and in the preferred construction tapered bosses 45 are provided on the ends of the central section 4I and are received in sockets in the inner ends of the sections 40 and 42.

v It is an important feature of the invention that.

the sectional bushing 31 is secured or retained on the pin 36 against displacement therefrom whereby the cutter A and' its bearing means may be handled, shipped and installed as a unit. The inner and outer ends of the pin 36 are peened over or riveted over at 46 and 41 respectively to cooperatewith the contiguous ends of the bushing sections 40 and 42, respectively.' If desired, the outer ends of the bushing sections 4|) and 42 may be Aslightly counter-bored to receive the riveted over parts 46 and 41. 'The peened over or riveted over end parts 46 and 41 of the pin 36 cooperate with the bushing sections 40 and 42 to maintain the assembly of the several bushing sections in proper end to end relation on the pin 36.

'I'he bushing 31 isprovided with races to oppose the races 35 on the interior of the cutter A. 'Ihe outermost corner of the inner bushing section 40 and the abutting comer of the central bushing section 4I have annular grooves which register to form a ball race 48. The ball race 48 is partially cylindrical in cross section and directly opposes one of the races 35. The corners of the sections 4I and 42 at their abutting ends are provided with annular grooves which register to form a ball race 49. The ball race 43 is partially cylindrical 'in cross section and directly opposes the other race 35 of the cutter A.

The balls 38 rotatably mount or support the cutter A on the sectional bushing 31. The balls 38 are arranged in the pairs or sets of opposing -races 35'and 48 and 35 and 43. The races 35 and 48 and 35 and 49 are shaped to accurately conform to thevballs 38 whereby the load capacity of the bearing is increased. Owing to the depth of the races 35, 48 and 4l, the rows or series of balls 38 assume the end thrusts in both directions, as well as the radial thrusts. Thus the cutter A is supported solely or entirely by the balls 38. A notch 50 is provided in the central bushing section .4I and communicates with the,

, on the interior race 48 to facilitate the insertion of the balls 38 in the opposing race 35.

In assembling the cutter A and its bearing a series of balls 38 may be arranged in the outermost race 35 and the bushing sections 4I and 42 inserted in the cutter opening 32 from its opposite ends whereby the balls are properly retained in the races 49 vand 35. The balls 38 are then successively inserted through4 the notch 58 into the other race 35 and when the required number of balls has been arranged in place the bushing section 40 is inserted ln the cutter opening 32 to' complete the race 48. 'I'he end parts 46 and 41 of the pin 36 may then be peened over or riveted over to secure the bushing sections 48, 4I and 42 against endwise movement and separation. The balls 38 cooperating with the opposing races 35 and 48, and 35l and 49, hold the cutter A against longitudinal movement and the end parts 46 and 4-1 of the pin36 hold the bushing 31 Aagainst displacement from the pin. Thus the several parts of the assembly are secured against separation whereby the assembly may be readily handled as a unit.

vThe invention provides simple yet very dependa-ble means for securing the bearing of the cutter A to the head II. The assembly of the cutter A and its bearing assembled in the form of a unit, as described' above, is moved upwardly relative to the head II to enter the cutter A in one of the recesses 24. When the cutter is thus entered in the recess v24 the projecting portion of the bushing section 42 is received in the notch 28 and the projecting portion of `the bushing section 48 is received\in the notch 121. The at surfaces 34 and 44 may shiftably or slidably engage the fiat side walls of the notches 21 and 28. The

cutter assembly or unit is moved upwardly to.

s When the cutter assembly and the washer 5I are the head II while the weld 53 rigidly secures the C-washer 5I, the bushing section 42 and the pin 36 to the outer wall portion of the head II. The welds 52 and 53 may be ground or machined oil smooth with the adjacent surfaces of the'head I I.

'I'he bushing sections 40 and 42 engage upwardly against inclined upper walls of the notches 21 and 28 so .that the cutterA secured to the head II, as just described, is rotatable about an axis inclined downwardly and outwardly relative to the vertical axis of the drill. The cutter A is mounted to project downwardly beyond the lower endof the headV II and to project inwardly somewhat at the lower end of the opening I2 to assist in making the annular cut in the earth formation and to trim the core for reception in the drill.

The outer cutters B are provided to cut the well bore to gauge. The cutters B'are frusta-conical having tapered or pitched peripheries. cutting teeth 55 are provided on the frusta-conical cutters B. The cutters B. have at ends and each is provided with a central longitudinal open- Suitable v ing 56. A tapered socket 51 is provided in the outer end of each cutter B to receive a boss 29. In accordance with the invention spaced ball races 58 are provided in the cutters B. In practice there may be two spaced ball races 58 provided in the wall of each cutter opening 56. The races 58 are partially circular in cross section and are of substantial depth.

The bearing means for rotatably supporting the outer cutters B are very similar to the means for supporting the inner cutters A. We will proceed with a description of the bearing means for understood that such description is equally apt plicable to the bearing means of the other cutters B.

The means for rotatably supporting an outer cutter B includesa pin 66, a sectional bushing 6| on the pin and balls 62 cooperating withthe races 58 and the bushing 6 I. The pin 68 is preferably a simple; cylindrical member of uniform diameter. The ends of the pin 68 are flat and the outer end of the pin is pitched to be substantially vertical when the cutter assembly is in place on the head II. The inner end of the pin 68 is pitched to be inclined downwardly and outwardly when the cutter assembly is secured in place on the head I I.

The bushing 6I is sectional and comprises an outer section 63, a central section 64 and an inner section 65. The sections 63, 64 and 65 are tubular and surround the pin 68. The sections 63, 64 andY 65 are generally cylindrical and of uniform diameter. The outer end of thesection 63 is pitched to lie in the same plane as the outer end of the pin 6I). The section 64 has its exposed end pitched to lie in the same plane as the inner end of the pin 60. The sections of the bushing 6I are arranged in abutting end to end relation. In accordance .with the invention the sectional bushing 6I is locked or retained on the pin 68 i whereby the cutter and bushing assembly may be handled-A as a unit. The pin 6I) has end parts 6I]a and Bub'peened over or riveted over to engage the exposed ends of the bushing sections 63 and 65,

respectively. The riveted over parts and 68h of the pin 60 prevent endwise displacement of the lbushing 6I from the pin. The sectional bushing 6I is longer than the cutter B and the projecting portions of the sections 63 and 65 are received in the notches 38 and 3I.- The bushing sections 63 and 65 preferably have flat side surfaces for cooperating with the side walls of the notches 38 and 3l.

Registering grooves are provided in the corners of the abutting ends of the sections 63 and 64 to form an annular ball race 66. 'I'he ball race 66 directly opposes one of the races 58 in the cutter B. The corners of the abutting ends of the sections 64 and 65 have registering grooves which form an annular ball race 61 directly opposing the other ball race 58. 'I'he races 66 and 61 are partially circular in cross section and are of sub-f stantial. depth. The balls 62 are provided in the.

sets or pairs of opposing races 58 and 66 and 58 and 61 and serve to rotatably support the cutter B on the sectional bushing 6I. The opposing races are of such depth that the balls 62 transmit ing parts and cutters.

oi' the bushing sections 63 and 65 in the notches 3l and 3l, respectively. The cutter assembly is then moved outwardly to a position where the boss 2l is properly received in the recess 54. It is to be understood that the cutter B has proper clearance with the boss 29 and the walls of the recess 25 when in the iinal position. 'I'he protruding portions of the bushing sections 63 and Il are engaged against the inclined upper walls of the notches 30 and Il. A c-washer B9 is provided to occupy the spacebetween the inner end of the cutter B and the inner wall of the recess 25. The 4-washer 89 is readily passed upwardly around the bushing section 65 to engage against the wall of the recess 25 and to have proper clearance with the cutter B. When the cutter assembly is in its proper position the unoccupied portions of the notches 30 and 3i are iilled with welds 'Il and 1|, respectively. The weld 10 rigidly secures or bonds the bushing section 63 and the pin l with the outer wall portion of the head I l while the weld 1I ilxes the washer 69, the bushing section I8 and the pin I0 to the inner wall portion o! the head Il. `The welds I0 and 1I may be finished to be iiush with the adjacent surfaces of the head Il.

It is believed that the' utility and practicability of the drill construction provided by this invention will be readily apparent from the foregoing detailed description. The cutters A and B are supported entirely by the sets or series of balls 38 and 62 to rotate with a minimum of friction. The bearing vassemblies are securely welded in the notches of the head Il to positively prevent loss or displacement of the bear- The cutter and bearing assemblies may be assembled at the place of manufacture and constitute units that may be shipped, handled and installed with ease. These cutter and bearing assemblies may be properly.

p assembled -at the place of manufacture to accuprisinga cutter having an opening, a pin passing through the opening, a bushing on the pin, balls rotatably supporting the cutter on the bushing, and riveted over parts on the pin holding the bushing on thepin whereby the assembly may be handled as a unit.

2. A cutter unit for a well drilling tool coxnprising, a cutter having an opening, a pin passing through the opening, a bushing on the pin, balls rotatably supporting the cutter on the bushing and transmitting both the end thrusts and the radial thrusts between the bushing and cutter, and parts on the pin at the ends of the bushing peened over to hold the bushing on the Din.

ing an opening, a pin passing through the opening, a sectional bushing on the pin, there being opposing ball races in the bushing and the' infterior of the cutter, balls cooperating with races to rotatably support the cutter, and riveted over 3. In a well arming tool', an assembly adapd tobe handled as a unit comprising a cutter ha 2l and to enter the protruding flat sided portions parts on the pin holding the bushing against displacement from the pin.

4. In a well drilling tool, an assembly adapted to be handled as a unit comprising a cutter having an opening, a pin passing through the opening, a sectional bushing on the pin, there being opposing ball races in the bushing and the interior of the cutter, balls cooperating with races to rotatably support the4 cutter, the races being of such depth that the balls transmit end thrusts between the bushing and cutter, and riveted over parts on the pin holding the bushing against displacement from the pin.

5. In a well drilling tool, an assembly adapted to be handled as a unit comprising a cutter hav ing an opening, a pin passing through the opening, a sectional bushing on the pin, there being opposing ball races in the bushing and the interior of the cutter, balls cooperating with the races to rotatably support the cutter, and end parts on the pin riveted over against theends of the bushing.

6. A well drilling tool comprising a body, a cutter having an opening, a ball bearing in the opening rotatably supporting the cutter and assuming end thrusts from the cutter in both directions, and welding securing the bearing to the body.

7. A well drilling tool comprising a body, a cutter having an opening, a pin extending into the opening, a bushing on the pin, balls rotatably supporting the cutter on the bushing, and a Weld securing the pin to the body.

8. A well drilling tool comprising a body, a cutter having an opening, a pin extending into the opening, a bushing on the pin, balls rotatably supporting the cutter on the bushing, and a Weld securing the bushing to the body.

9. A well drilling tool comprising a body, a cutter having an opening, a pin extending into the opening, a bushing on the pin, balls rotatably supporting the cutter on the bushing, and a weld securing the pin and bushing to the body.

10. A well drilling tool comprising a body having spaced supports, a cutter between the supports having an opening, a pin extending through the opening, a ball bearing on the pin rotatably supporting the cutter, and welds securing the bearing to the supports.

11. A well drilling tool comprising a body having spaced supports, a cutter between the supports having an opening, a pin extending through the opening, a sectional bushing on the pin, balls cooperating with the bushing and the cutter rotatably supporting the cutter and transmitting the end thrusts between the cutter and bushing, and welds securing the pins to the 12. In a. well drill, spaced supports having openings, a cutter between the supports having an opening, a bearing extending through the opening in the cutter and having its end portions received in the first mentioned openings, balls rotatably supporting the cutter on the bearing, and welds securing the said bearing portions in the said first mentioned openings.

13. In a well drill, spaced supports having notches, a cutter between the supports having an opening, a pin extending through the opening, a bushing on the pin h'aving its end portions received in the notches, the bushing and cutter opening having opposed races, balls in the races rotatably supporting the cutter, and welding securing the said end portions of the bushing in the notches.

1i. in e, wel! drill, spaced supports having notches, o cutter between the supports having an opening, a. pin extending through the opening, a bushing on the pin having its end portions re ceived in the notches, the bushing and cutter opening having opposed races, balls in the races rototably supporting the cutter, and Weids in the notches securing the end por-tions oi the pin and said end portions of the bushing to the supports.

l5. In o. well drill, spaced supports having notches, a.. cutter between the supports having an opening, a pin extending through the opening, a bushing on the pin having its end portions receivedl in the notches, the bushing ond cutter opening having opposed races, balls in the races rotatably supporting the cutter, a washer on the bushing between one of saidsupportsand the cutter, e weld in the notch of said support securing the washer and the adjacent end portions of the bushing and pin to said support, and n weld in the notch of the other support secliiing the adjacent enel portions of the bushing ond pin to said other support. 

